RE: Questions on lab 3

Edwin Chan (echan@ece.ubc.ca) Sun, 29 Oct 2000 21:19:38 -0800 

From: "Edwin Chan" <echan@ece.ubc.ca>
Subject: RE: Questions on lab 3
Date: Sun, 29 Oct 2000 21:19:38 -0800





----- Original Message -----
From: "Shereen Pang" <shereen@interchange.ubc.ca>
To: <eece379@fs3.ece.ubc.ca>
Sent: Sunday, October 29, 2000 11:51 PM
Subject: Questions on lab 3


> Hi all:
>
> I have 3 questions on lab 3.
>
> 1. How do we use generics in VHDL? I realized that the example given on
> page 5 of the 3rd handout (entity nregister) is not complete, ie, it
> doesn't compile because I didn't give width a value  in generic (width:
> integer);
Generics is an entity can be declared with the size underfined until the
component is used.

The code on page 5 is the part that declared the nregister.  The code on
page 6 is the part of code that USE the nregister.


> 2. assembly code: how do we print an asterisk(*) on screen? how many
> bytes does asterisk has?
Each ASCII code represent a character.  For (*), move 2AH on dl.

I attached the ASCII table as pdf format in this email.


> 3. Assembly code in lab 2: Why is it when we read a character from the
> keyboard with MOV AH, 01H, the value of the keyboard input is stored in
> AL? I assumed it's stored in AL because we subtract AL with 30H and
> later move AL to DX.
A series of commands is needed to obtain a character from a keyboard.  MOV
AH, 01H is part of the code.  If you look the ASCII table, you cleanly find
that the character '0' is represented by 30H.  ASCII code is a STANDARD code
you have to deal with.

> can somebody help me out? thanks.
>
> Shereen Pang
>
>
>